This application claims priority to FRANCE 9904103 filed Apr. 1, 1999.
The present invention relates to a nail varnish or nailcare composition comprising an aqueous dispersion of polymer particles, a plasticizer and a coalescent. The invention also relates to a method of making up and/or caring for the nails, especially human nails or false nails.
The nail varnish or nailcare composition can be employed as a varnish base, as a nail makeup product, as a finishing composition, also referred to as a xe2x80x9ctopcoatxe2x80x9d, for application over a nail makeup product, or else as a cosmetic nailcare product.
Nail varnish compositions are known which comprise aqueous dispersions of particles of a film-forming polymer. The properties of these varnishes are not always satisfactory. In particular, the film may exhibit poor adhesion to the nail and/or may not be sufficiently bright. Moreover, the varnish, after drying, is often difficult to remove, even with the conventional removers based on acetone or ethyl acetate, for example.
An object of the present invention is to provide an aqueous nail varnish medium exhibiting good properties such as adhesion to the nail and brightness and also removability with the conventional removers based on acetate and/or ethyl acetate.
The inventors have found that such a nail varnish can be obtained by employing an aqueous dispersion of polymer particles in combination with selected solvents.
The invention provides a nail varnish or nailcare composition comprising an aqueous dispersion of polymer particles, wherein:
the polymer is an acrylic polymer having at least one glass transition temperature (Tg) greater than or equal to 45xc2x0 C. and a minimum film-forming temperature (MFT) such that
Tgxe2x88x92MFTxe2x89xa620xc2x0 C.,
and wherein the composition further comprises:
at least one first organic solvent having a boiling point measured at ambient pressure of greater than or equal to 225xc2x0 C., and
at least one second organic solvent having a boiling point measured at ambient pressure ranging from 70xc2x0 C. to 180xc2x0 C.
The invention additionally provides a cosmetic makeup and/or nailcare method which comprises applying a composition as defined above to the nails.
The invention further provides for the use, in a nail varnish or nailcare composition, of an acrylic polymer in aqueous dispersion having at least one glass transition temperature (Tg) greater than or equal to 45xc2x0 C. and a minimum film-forming temperature (MFT) such that Tgxe2x88x92MFTxe2x89xa620xc2x0 C., of a first organic solvent having a boiling point measured at ambient pressure of greater than or equal to 225xc2x0 C., and of a second organic solvent having a boiling point measured at ambient pressure ranging from 70xc2x0 C. to 180xc2x0 C., to obtain a film which is removable with acetone and/or with ethyl acetate and/or which is adherent to the nail and/or bright.
Advantageously, the acrylic polymer has at least one glass transition temperature (Tg) greater than or equal to 45xc2x0 C. and a minimum film-forming temperature (MFT) such that Tgxe2x88x92MFTxe2x89xa610xc2x0 C., and more preferably xe2x89xa65xc2x0 C.
Preferably, the polymer in aqueous dispersion has a glass transition temperature Tg of less than 70xc2x0 C. and more preferably of from 55xc2x0 C. to 65xc2x0 C. The glass transition temperature (Tg) is measured by DSC (Differential Scanning Calorimetry) in accordance with the standard ASTM D3418-97.
The acrylic polymer can be a styrene/acrylate copolymer and, in particular, a polymer selected from copolymers obtained by polymerizing at least one styrene monomer and at least one (C1-C18) alkyl (meth)acrylate monomer.
As a styrene monomer which can be used in the invention, mention may be made of styrene or alpha-methylstyrene, preferably styrene.
The (C1-C18) alkyl (meth)acrylate monomer is preferably a (C1-C12) alkyl (meth) acrylate and more preferably a (C1-C10) alkyl (meth)acrylate.
The (C1-C18) alkyl (meth)acrylate monomer is selected from methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate, butyl methacrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, lauryl (meth)acrylate and stearyl (meth)acrylate.
Advantageously, the acrylic polymer in aqueous dispersion has solubility properties at 25xc2x0 C. in organic solvents, corresponding to the average Hansen solubility parameters dD, dP and dH, which satisfy the following conditions:
dD=17.5
dP=7
dH=7.6
with a radius R ranging from 5 to 10, and preferably from 5 to 6.
The definition of the solvents in the three-dimensional solubility space according to Hansen is described in the article by C. M. Hansen: xe2x80x9cThe three dimensional solubility parametersxe2x80x9d, J. Paint Technol. 39, 105 (1967), the disclosure of which is specifically incorporated by reference herein.
dD characterizes the London dispersion forces resulting from the formation of dipoles induced on molecular impact.
dP characterizes the Debye interaction forces between permanent dipoles and the Keesom interaction forces between induced dipoles and permanent dipoles.
dH characterizes the specific interaction forces (of the hydrogen bonding, acid/base, donor/acceptor type, etc.).
The parameters dD, dP and dH are expressed in (J/Cm3)xc2xd.
The radius R corresponds to the distance, in the Hansen solubility parameter space, separating an organic solvent from the point in the space corresponding to dD=17.5; dP=7; dH=7.6, R meeting the following condition:
5Jxe2x88x92xc2xdcmxe2x88x92{fraction (3/2)}xe2x89xa6Rxe2x89xa610Jxc2xdcmxe2x88x92{fraction (3/2)},
in which:
  R  =                    4        ⁢                              (                                          δ                                  s                  d                                            -              17.5                        )                    2                    +              xe2x80x83            ⁢                        (                                    δ                              s                p                                      -            7                    )                2            +              xe2x80x83            ⁢                        (                                    δ                              s                h                                      -            7.6                    )                2            
where xcex4sd, xcex4sp, xcex4sh are the Hansen solubility parameters of an organic solvent for which the acrylic polymer used in the present invention has solubility properties. The definition of the radius R is known from the work by Allan F. M. Barton, CRC Handbook of solubility parameters and other cohesion parameters, Second edition, 1991, pages 95 to 109, the disclosure of which is specifically incorporated by reference herein.
As the acrylic polymer in aqueous dispersion, use may be made in accordance with the invention of the styrene/acrylate copolymer marketed under the name JONCRYL SCX-8211 by the company Johnson.
In accordance with one particular embodiment of the invention, the composition may comprise as sole polymer in aqueous dispersion the acrylic polymer defined above.
The acrylic polymer in aqueous dispersion may be present in an amount, in terms of dry matter, which is effective for forming a film, preferably in an amount ranging from 3% to 50% by weight, relative to the total weight of the composition, and more preferably from 10% to 40% by weight.
The first organic solvent present in the composition, which is also called the plasticizer, makes it possible to plasticize the polymer in aqueous dispersion. Preferably, the first organic solvent can have a distribution coefficient D of less than or equal to 0.1. The distribution coefficient is determined in accordance with the teaching of xe2x80x9cA method to predict the distribution coefficient of coalescing agents between latex particles and the water phase,xe2x80x9d Progress in Organic Coatings, vol. 30, 1997, pp. 173-177, the disclosure of which is specifically incorporated by reference herein.
The first organic solvent according to the invention is preferably selected from diisobutyl adipate, the ester of tertbutyl acid and 2,2,4-trimethylpentane-1,3-diol, diethyl adipate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, butyl 2-ethylhexyl phthalate, dimethyl sebacate, dibutyl sebacate, ethyl stearate, 2-ethylhexyl palmitate, dipropylene glycol n-butyl ether, and mixtures thereof.
Even more preferably, the first organic solvent may be selected from diisobutyl adipate, the ester of tertbutyl acid and 2,2,4-trimethylpentane-1,3-diol, dipropylene glycol n-butyl ether, and mixtures thereof.
Preferably, the first organic solvent has a boiling point measured at ambient pressure of less than or equal to 285xc2x0 C., preferably less than or equal to 270xc2x0 C. and, more preferably, less than or equal to 250xc2x0 C. In the present specification, the boiling point values are to be considered accurate to xc2x12xc2x0 C. owing to the uncertainties of boiling point measurement.
The first organic solvent can be present in the composition according to the invention in an amount preferably ranging from 0.1% to 20% by weight, relative to the total weight of the composition, and more preferably from 0.5% to 10%.
The second organic solvent present in the composition, which is also called the coalescent, promotes the coalescence of the polymer particles in aqueous dispersion. Preferably, the second organic solvent may have a distribution coefficient Dxe2x80x2 of greater than or equal to 0.5, measured in accordance with the above-referenced xe2x80x9cA method to predict the distribution coefficient of coalescing agents between latex particles and the water phase,xe2x80x9d Progress in Organic Coatings, vol. 30, 1997, pp.173-177.
As the second organic solvent, use may be preferably made according to the invention of propylene glycol n-butyl ether, dipropylene glycol dimethyl ether, propylene glycol methyl ether acetate, propylene glycol propyl ether, methyl lactate, ethyl lactate, isopropyl lactate, and mixtures thereof.
More preferably, the second organic solvent is selected from propylene glycol n-butyl ether, dipropylene glycol dimethyl ether, isopropyl lactate, and mixtures thereof.
Preferably, the second organic solvent has a boiling point measured at ambient pressure ranging from 90xc2x0 C. to 180xc2x0 C., and more preferably from 150xc2x0 C. to 180xc2x0 C.
The second organic solvent may be present in the composition in an amount preferably ranging from 2% to 15% by weight, relative to the total weight of the composition, more preferably from 3% to 10%.
The composition of the invention may further comprise at least one additive chosen from thickeners, leveling agents, wetting agents, dispersants, antifoams, preservatives, UV screens, dyes, pigments, active principles, surfactants, moisturizers, perfumes, neutralizing agents, stabilizers, antioxidants, and combinations thereof.